title: Lesion edge preserved direct average strain estimation for ultrasound elasticity imaging.
abstract: Elasticity imaging techniques with built-in or regularization-based smoothing feature for ensuring strain continuity are not intelligent enough to prevent distortion or lesion edge blurring while smoothing. This paper proposes a novel approach with built-in lesion edge preservation technique for high quality direct average strain imaging. An edge detection scheme, typically used in diffusion filtering is modified here for lesion edge detection. Based on the extracted edge information, lesion edges are preserved by modifying the strain determining cost function in the direct-average-strain-estimation (DASE) method. The proposed algorithm demonstrates approximately 3.42-4.25 dB improvement in terms of edge-mean-square-error (EMSE) than the other reported regularized or average strain estimation techniques in finite-element-modeling (FEM) simulation with almost no sacrifice in elastographic-signal-to-noise-ratio (SNRe) and elastographic-contrast-to-noise-ratio (CNRe) metrics. The efficacy of the proposed algorithm is also tested for the experimental phantom data and in vivo breast data. The results reveal that the proposed method can generate a high quality strain image delineating the lesion edge more clearly than the other reported strain estimation techniques that have been designed to ensure strain continuity. The computational cost, however, is little higher for the proposed method than the simpler DASE and considerably higher than that of the 2D analytic minimization (AM2D) method.
authors.affiliation: Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh.
authors.forename: Mohammad Arafat
authors.initials: MA
authors.lastname: Hussain
authors.forename: Farzana
authors.initials: F
authors.lastname: Alam
authors.forename: Sharmin Akhtar
authors.initials: SA
authors.lastname: Rupa
authors.forename: Rayhana
authors.initials: R
authors.lastname: Awwal
authors.forename: Soo Yeol
authors.initials: SY
authors.lastname: Lee
authors.forename: Md Kamrul
authors.initials: MK
authors.lastname: Hasan
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016217:Ultrasonography, Mammary / Q000379:methods*; D055815:Young Adult
keywords: Average strain; Elastography; Instantaneous strain; Normalized cross-correlation; Ultrasonic imaging